Damage control is in full swing in the increasingly contentious battle between Mel Gibson and his ex-girlfriend, Oksana Grigorieva, over their 7-month-old daughter, Lucia. In the wake of dueling restraining orders (hers after he allegedly got physical with her; his to keep her inflatable lips zipped), insiders on both sides are blabbing about what may have led to the current mess.

The legal showdown seemingly centers on the events of January 6, 2010, when the Oscar winner, 54, whose image has never recovered from his anti-Semitic-tinged DUI bust in 2006, and the Russian singer, 40, purportedly got into an argument at his Malibu estate.

"Oksana was completely out of control that day, screaming and shaking Lucia like a ragdoll," a snitch contends to People magazine. "Mel stepped in to stop her from injuring the baby."

Sources spill more supposed details to TMZ, claiming that Grigorieva ran to the backyard with Lucia and "threw herself on the ground," then returned to the house and began shaking the child.

At that point, the spies concede, there was "physical contact" between the two, but they deny Gibson hit Grigorieva and insist his only concern was to protect Lucia.

"The allegation that Oksana is in fear of Mel is ridiculous," scoffs the People snitch. "From January to March, she traveled with Mel to London and Paris at her insistence. This is all an attempt to gain financial advantage over him."

The fallout from the alleged incident came to a head just before Father's Day, when Grigorieva reportedly refused to allow Gibson a visit that had already been hammered out in a mediated custody agreement following their April split.

According to TMZ, Oksana was unhappy with the custody arrangement she signed, in which she received primary physical custody and Gibson was allowed visitation, including overnight visits, a deal that would eventually segue into 50-50 custody.

Oksana supposedly was seeking to limit (or possibly cut off) Mel's contact with Lucia, and took out the restraining order the day after Father's Day, which led to a legal showdown on Tuesday.

"He was as frustrated as any father would be when they're kept away from their child," another Gibson source tells the mag. "He was with all his kids [he has six sons and a daughter with Robyn, his not-quite-ex-wife of 30 years] and family and the one person missing was Lucia. Oksana is not putting the interest of their daughter first."

But a Grigorieva source denies the situation boiled over because she was keeping Lucia away from the actor: "That is absolutely not what caused all this. There's other reasons in this case that brought it to where it is today. Oksana doesn't feel the custody agreement is fair."

Grigorieva made her position clear in a statement to Radar, saying, "He's playing dirty. The truth will come out."

According to TMZ, Gibson's attorney was able to have the restraining order modified to allow him access to Lucia, although a bombshell apparently emerged during the hearing.

Seems Oksana, who also has a 13-year-old son with ex-boyfriend Timothy Dalton, secretly recorded arguments she'd had with Mel. The judge reportedly ordered the tapes sealed and told her to keep cakehole her closed about the contents.

What do you think (besides that perhaps Gibson should have appreciated wife Robyn a whole lot more)? Tell us in the comments.